new model for bubble-induced turbulence based on direct numerical simulation data


new model for bubble-induced turbulence based on direct numerical simulation data

Ma, T.; Santarelli, C.; Ziegenhein, T.; Lucas, D.; Fröhlich, J.

Three main issues are addressed in the present study. First, an appropriate time scale is selected with the aid of the energy spectra determined on the basis of the DNS data. Then, links between the unclosed terms in the transport equations of the turbulence quantities and the DNS data for small bubbles are established. Third, a suitably chosen iterative procedure employing the full Reynolds-averaged model provides suitable coefficients for the closure of the terms resulting from BIT while largely removing the influence of others. Here, using DNS data with iterations to obtain term-by-term match (Figure 1b) in the model equations avoids pitfalls of ad hoc models targeting the TKE only. At the same time these results validate the closure, exhibiting very good agreement with the DNS and better performance than the standard closures. Beyond the resulting model itself the study also furnishes a systematic procedure which is of general use. The model is now ready for use and can be employed in practical Euler-Euler simulations.

  • Lecture (Conference)
    The 3rd International Conference on Numerical Methods in Multiphase Flows, 26.-29.06.2017, Tokyo, Japan

Permalink: https://www.hzdr.de/publications/Publ-26594
Publ.-Id: 26594